Peripherals in a computer system generate interrupts to notify the processor of events that merit the processor's attention. In a virtualized computing system, the interrupts include virtual interrupts directed to guest operating systems running on virtual machines. A virtual interrupt controller delivers the virtual interrupts to the guest operating systems, thereby offloading interrupt processing from the hypervisor and improving system performance. However, a bug, attacking program, or other anomaly may cause one or more peripherals to generate an excessive number of virtual interrupts, degrading system performance and potentially overwhelming all of the guest operating systems. The hypervisor may be unable to detect and protect against the excessive virtual interrupts, because processing of virtual interrupts has been offloaded to the virtual interrupt controller.